Improved check if highlighter is enabled.

app/assets/javascripts/app/controllers/ticket_zoom.js.coffee

@@ -93,7 +93,8 @@ class App.TicketZoom extends App.Controller
 
     App.Event.trigger('ui::ticket::shown', { ticket_id: @ticket_id } )
 
-    if !@highlighed
+    # inital load of highlights
+    if @highligher && !@highlighed
       @highlighed = true
       @highligher.loadHighlights()
 

app/assets/javascripts/app/controllers/ticket_zoom/higlighter.js.coffee

@@ -94,6 +94,7 @@ class App.TicketZoomHighlighter extends App.Controller
 
   # for testing purposes the highlights get stored in localStorage
   loadHighlights: ->
+    return if !@isRole('Agent')
     @el.closest('.content').find('.textBubble-content').each( (index, element) =>
       article_id = $(element).data('id')
       article    = App.TicketArticle.find(article_id)